1. Field of the Invention
The present invention pertains refers to a modular device for the putting into motion of loads with at least three degrees of freedom.
2. Description of the Prior Art
The French patent No. 2 745 656 describes a known compact device for the putting into motion of loads such as a simulator cabin with three degrees of freedom. This device is moved by three electric motors and enables the load to be moved along the axes of pitch, roll and vertical displacement with maximum possible amplitudes of angular motion that are limited to approximately .+-.13.degree.. This is enough for certain simulation applications for which the compactness of the device is a major criterion.
However, certain applications require greater maximum amplitudes of angular motion, namely values in the range of .+-.25, in order to enable the reproduction of sensations specific to the requirements of simulation. These applications are, for example, the simulation of movements in highly uneven or mountainous terrain.
In addition, there are known major systems with six degrees of freedom implementing six jacks, making it possible to obtain high maximum amplitudes of angular motion. However, these systems are very costly, in particular because of the use of hydraulic jacks and their control device (with power unit and hydraulic jacks, the simultaneous control of six axes etc.).
There is a known low-cost device, described in the document EP-A-0 373 029, for putting a load into motion. This device uses three electric motors. On the driven shaft of each electric motor, there is mounted a crank, connected by a suspended-rod type hinge to a corresponding tip or corner of a triangular platform. This known device is satisfactory in certain applications that do not require high maximum amplitudes of angular motion (in terms of roll and/or pitch motions) of the platform (they require amplitudes of less than about 13.degree.). The suspended-rod type hinge and the cardan joints connecting it to the platform prevent higher maximum amplitudes of angular motion from being communicated to this platform.